// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2020 Facebook

#include <stdbool.h>
#include <linux/bpf.h>
#include <stdint.h>
#include <bpf/bpf_helpers.h>
#include "bpf_misc.h"

char _license[] SEC("license") = "GPL";

struct {
        __uint(type, BPF_MAP_TYPE_RINGBUF);
} ringbuf SEC(".maps");

const volatile int batch_cnt = 0;
const volatile long use_output = 0;
const volatile bool bench_producer = false;

long sample_val = 42;
long dropped __attribute__((aligned(128))) = 0;
long hits __attribute__((aligned(128))) = 0;

const volatile long wakeup_data_size = 0;

static __always_inline long get_flags()
{
        long sz;

        if (bench_producer)
                return BPF_RB_NO_WAKEUP;

        if (!wakeup_data_size)
                return 0;

        sz = bpf_ringbuf_query(&ringbuf, BPF_RB_AVAIL_DATA);
        return sz >= wakeup_data_size ? BPF_RB_FORCE_WAKEUP : BPF_RB_NO_WAKEUP;
}

SEC("fentry/" SYS_PREFIX "sys_getpgid")
int bench_ringbuf(void *ctx)
{
        long *sample, flags;
        int i;

        if (!use_output) {
                for (i = 0; i < batch_cnt; i++) {
                        sample = bpf_ringbuf_reserve(&ringbuf,
                                                     sizeof(sample_val), 0);
                        if (!sample) {
                                __sync_add_and_fetch(&dropped, 1);
                        } else {
                                *sample = sample_val;
                                flags = get_flags();
                                bpf_ringbuf_submit(sample, flags);
                                if (bench_producer)
                                        __sync_add_and_fetch(&hits, 1);
                        }
                }
        } else {
                for (i = 0; i < batch_cnt; i++) {
                        flags = get_flags();
                        if (bpf_ringbuf_output(&ringbuf, &sample_val,
                                               sizeof(sample_val), flags))
                                __sync_add_and_fetch(&dropped, 1);
                        else if (bench_producer)
                                __sync_add_and_fetch(&hits, 1);

                }
        }
        return 0;
}